Two experiments were carried out to investigate the effects of image-arousal and semantic congruity on free and cued recall. The experiments involved orienting task in incidental memory paradigms. Fifty subjects were asked to rate the degree of semantic congruity between a sentence frame and its target in Experiment I. In Experiment II, 40 subjects were asked to rate the vividness of image aroused by the sentence frame and its target. Experiment I and II results showed that congruity effects were lacking when the sentence frame and its target aroused vivid image, but congruity provided for higher free and cued recall when the sentence frame and its target aroused dull image. The above inconsistent effects of congruity were discussed in terms of bizarreness of mental image and distinctiveness in retrieval.